1. Field of Invention
This invention relates to a storage system capable of configuring a failover system by using two storage processing devices to which storage media are connectable, and to a failover control method used in the storage system.
2. Descriptions of the Related Art
Heretofore, some systems have employed a failover configuration to improve the reliability of the systems. In a system employing the failover configuration (failover system), for example, one of two servers serves as a main and the other serves a backup. The main server performs processing for tasks under normal condition. When the main server fails, the backup server takes over the processing for the tasks.
In recent years, storage processing devices called network attached storages (NAS) have been widely used. Plural storage media can be connected to the NAS, and various types of content data such as video and audio data can be stored in the storage media. Upon receiving a request for content data from a terminal device via a network, the NAS transmits the requested content data to the terminal device via the network. The terminal device reproduces the content of the received content data.
A proposal has been made to build a failover configuration for a system using NAS. In a failover system including two NAS, one NAS is the main and the other NAS is the backup. The two NAS can configure the failover system if the storage capacity of the storage media connected to the backup NAS is equal to or larger than the storage capacity of the storage media connected to the main NAS (for example, see Japanese Patent Application Publication No. 2006-99440). In the case where the two NAS can configure the failover system, as similar to the above system, the main NAS performs processing for tasks under normal conditions, and the backup NAS takes over the processing for the tasks when the main NAS fails.